1. Field of the Invention
This invention relates to a quick release mechanism, more particularly to a quick release mechanism which is easy to assemble and which has provisions to assure proper operation thereof even after a long period of use.
2. Description of the Related Art
Referring to FIG. 1, a conventional quick release mechanism is shown to comprise a cylindrical rod 12 which is formed with a diametrically extending screw hole 122. A mounting shaft 14 has a first threaded end 141 connected threadably to the screw hole 122 of the cylindrical rod 12. A locking nut 15 is connected threadably to a second threaded end 142 of the mounting shaft 14. A pressing member 13 is sleeved on the mounting shaft 14 adjacent to the cylindrical rod 12 and has a concave surface 132 which faces the cylindrical rod 12. A manually operated lever 11 has an end portion 113 and a pair of spaced lugs 112 which extend longitudinally from the end portion 113 and which are formed with aligned eccentric holes 114 that receive respectively two opposed ends of the cylindrical rod 12 therein. Each of the lugs 112 has a cam edge (112a) which complements and which is in contact with the concave surface 132 of the pressing member 13.
Referring to FIG. 2, the conventional quick release mechanism is used to secure a hub 21 of a bicycle wheel on a bicycle fork. As illustrated, the mounting shaft 14 extends into the hub 21. The lever 11 is in a tightened position, wherein the lever 11 is generally perpendicular to the mounting shaft 14, the cam edges (112a) of the lever 11 push the pressing member 13 to abut against an outer side of one of the prongs 22 of the bicycle fork, and the locking nut 15 is pulled to abut against an outer side of the other one of the prongs 22 of the bicycle fork so as to clamp tightly the hub 21 to the bicycle fork. To release the hub 21 from the bicycle fork, the lever 11 is operated to pivot about the cylindrical rod 12 to a slack position, wherein the lever 11 is generally perpendicular to the mounting shaft 14, the locking nut 15 is biased by a spring means (not shown) to move axially away from the outer side of the corresponding prong 22 of the bicycle fork, and the pressing member 13 is biased by another spring means (not shown) to move axially away from the outer side of the corresponding prong 22 of the bicycle fork.
Referring to FIGS. 2 and 3, it should be noted that the concave surface 132 of the pressing member 13 must be initially rotated to an appropriate position corresponding to the cam edges (112a) of the lever 11 before moving the lever 11 from the slack position to the tightened position every time, thereby inconveniencing the assembly of the conventional quick release mechanism. Furthermore, since a space (A) formed between the lugs 112 is not filled up by the cylindrical rod 12, dirt (not shown) or the like will accumulate in the space (A) and will harden after a period of use, thereby hindering pivoting movement of the lever 11 between the tightened position and the slack position.